This model is designed to remove moisture from a your filament spool.
This model is inspired by others I have seen here and there.
I have sized it so that it can be printed on both the BambuLab Mini and X1C.
Use a 4mm hexagonal, allen wrench to screw the rollers…Not too tight, as it might break. Remember, it's not metal.
In case you are using the bearings, be careful to place the washer as shown in one of the photos.
Regarding the rectangular hygrometer, I bought it on AliExpress but should be able to find it also on amazon:
https://www.aliexpress.com/item/1005003075779370.html
I bought the cereal boxes on Amazon:
The model was designed in such a way as to be able to accommodate silica gel. I bought a 2kg pot of silica gel on Amazon: